Electrosurgical Devices with Wire Electrode And Methods of Use Thereof

ABSTRACT

The invention provides an electrosurgical device and methods of use thereof. In one embodiment, the device may comprise a handle, a shaft distal to the handle, a first electrode tip and a second electrode tip adjacent a distal end of the shaft, with the first electrode tip spaced from the second electrode tip and wherein the first electrode tip comprises a first U-shaped electrode and the second electrode tip comprises a second U-shaped electrode, and at least one fluid outlet. In another embodiment, the device may comprise a handle, a shaft distal to the handle, and a first electrode and a second electrode adjacent a distal end of the shaft with the first electrode coplanar with the second electrode and comprising a wire electrode having a U-shape which surrounds a perimeter of the second electrode and is spaced from the second electrode by an aperture.

FIELD

This invention relates generally to the field of medical devices,systems and methods for use upon a human body during surgery. Moreparticularly, the invention relates to electrosurgical devices, systemsand methods that provide for cutting of tissue in addition tocoagulation, hemostasis and sealing of tissue to inhibit blood and otherfluid loss during surgery such as abdominal, orthopedic, head, spine andthoracic surgery as well as general surgery of the body.

BACKGROUND

Fluid-assisted electrosurgical devices have been developed which, whenused in conjunction with an electrically conductive fluid such assaline, may be moved along a tissue surface, without cutting the tissue,to seal tissue to inhibit blood and other fluid loss during surgery.However, to cut tissue the surgeon must utilize a second device, whichnecessitates delays associated when switching between devices. What isstill needed is an electrosurgical device which is capable of cutting oftissue as well as providing fluid-assisted sealing of tissue to inhibitblood and other fluid loss during surgery, as well as inhibitundesirable effects of tissue desiccation, tissue sticking to theelectrode, tissue perforation, char formation and smoke generation. Whatis also needed is an electrosurgical device which cuts tissue withreduced lateral thermal spread and damage to adjacent tissue.

SUMMARY OF THE INVENTION

The invention, in one embodiment, may provide an electrosurgical deviceto treat tissue in a presence of a fluid from a fluid source andradio-frequency power from a radio-frequency power source, particularlyproviding a bipolar power output and a monopolar power output. Thedevice may comprise a distal portion comprising a first electrode tip, asecond electrode tip and at least one fluid outlet. The first and secondelectrode tips may be configured as bipolar electrodes, configured toreceive the bipolar power output from the radio-frequency power sourcetreat tissue, particularly by moving along a tissue surface in apresence of a bipolar power output and a fluid provided simultaneouslyfrom the distal portion. At least one of the electrode tips may beconfigured as a monopolar electrode, configured to receive the monopolarpower output from the radio-frequency power source and provide anelectrosurgical cutting edge, which may be configured to cut tissue bymoving along a tissue surface in a presence of monopolar power outputprovided from the distal portion.

In certain embodiments, the electrosurgical device may comprise ahandle, a shaft distal to the handle, a first electrode tip and a secondelectrode tip adjacent a distal end of the shaft, with the firstelectrode tip spaced from the second electrode tip and wherein the firstelectrode tip comprises a first wire electrode having a U-shape and thesecond electrode tip comprises a second wire electrode having a U-shape,and at least one fluid outlet.

Each of the first and second U-shape electrodes may comprise an arcuatedistal segment and two longitudinal segments extending distally relativeto a distal end of the shaft. The arcuate distal segment of each of thefirst and second U-shape electrodes may be arcuate from one longitudinalsegment to the other longitudinal segment, and may be semicircularbetween the two longitudinal segments. At least one of the U-shapeelectrodes may provide a cutting edge, which may be an electrosurgicalcutting edge and may be arranged along a longitudinal length of theU-shape electrode. The cutting edge may particularly be straight(linear).

The first electrode and a second electrode may be formed from metalwire. The metal wire may be single strand (solid core) wire, and moreparticularly circular single strand wire. The metal wire may bestainless steel wire. In this manner, the electrodes may have a lowmass, which may allow the electrodes to dissipate heat and cool quicklyduring and after tissue treatment, which may inhibit damage to adjacenttissue (not to be treated) due to lateral thermal spread.

The at least one fluid outlet may be located a distal end of the shaft.More particularly, the fluid outlet may be located between the twolongitudinal segments of at least one of the U-shape electrodes.

The at least one fluid outlet may comprise a first fluid outlet andsecond fluid outlet. The first fluid outlet may be located between thetwo longitudinal segments of the first U-shape electrode, and the secondfluid outlet is located between the two longitudinal segments of thesecond U-shape electrode.

The U-shape electrodes may be coplanar. The two longitudinal segments ofthe first U-shape electrode and the two longitudinal segments of thesecond U-shape electrode may be parallel, and more particularly in asingle plane.

One longitudinal segments of each of the first and second U-shapeelectrodes may be medial longitudinal segment and the other longitudinalsegment may be lateral longitudinal segment.

The two longitudinal segments of the second U-shape electrode may bemedial relative to the two longitudinal segments of the first U-shapeelectrode.

The first U-shape electrode may surround a perimeter of the secondU-shape electrode, and the second U-shape electrode may be locatedwithin a U-shape aperture defined by the first U-shape electrode.

Each of the first and second U-shape electrodes may comprise an arcuatedistal segment, and the arcuate distal end segments may be concentric.

The first U-shape electrode and the second U-shape electrode may have atleast one of a same size and a same shape, and a position of firstU-shape electrode and a position of the second U-shape electrode may befixed relative to one another.

In certain embodiments, the electrosurgical device may comprise ahandle, a shaft distal to the handle, a first electrode tip and a secondelectrode tip adjacent a distal end of the shaft, with the firstelectrode tip spaced from the second electrode tip and wherein the firstelectrode tip comprises a first electrode having a first arcuate wireportion forming an arc of at least 180 degrees and the second electrodetip comprises a second electrode having a second arcuate wire portionforming an arc of at least 180 degrees, and at least one fluid outlet.

In certain embodiments, the electrosurgical device may comprise ahandle, a shaft distal to the handle, and a first electrode and a secondelectrode adjacent a distal end of the shaft with the first electrodecoplanar with the second electrode and comprising a wire electrodehaving a U-shape which surrounds a perimeter of the second electrode andis spaced from the second electrode by an aperture. In certainembodiments, the second electrode may comprise a wire electrode having alinear segment, a U-shape or a blade shaped member. The device may alsocomprise at least one fluid outlet.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of one embodiment of a system of the presentinvention having an electrosurgical unit in combination with a fluidsource and handheld electrosurgical device;

FIG. 2 a front perspective view of the electrosurgical unit of FIG. 1;

FIG. 3 is a graph of the bipolar RF power output versus impedance forthe electrosurgical unit of FIG. 1;

FIG. 4 is graph showing a relationship of fluid flow rate Q in units ofcubic centimetres per minute (cc/min) on the Y-axis, and the RF powersetting P_(S) in units of watts on the X-axis;

FIG. 5 is a perspective view of an electrosurgical device according tothe present invention;

FIG. 6 is a plan view showing the various electrical connections andconductors of the device of FIG. 5 with the electro surgical unit ofFIG. 1;

FIG. 7 is a plan view showing a first embodiment of the various fluidconnections and passages of the device of FIG. 5 with theelectrosurgical unit and fluid source of FIG. 1;

FIG. 8 is a plan view showing a second embodiment of the fluidconnections and passages of the device of FIG. 5 with theelectrosurgical unit and fluid source of FIG. 1;

FIG. 9 is a close-up view of the shaft of the device of FIG. 5;

FIG. 10 is a close-up cross-sectional view of the electrodes of thedevice of FIG. 5. taken along line 10-10 of FIG. 5;

FIG. 11 is a close-up cross-sectional view of another embodiment of theelectrodes of the device of FIG. 5 taken along line 10-10 of FIG. 5;

FIG. 12 is a close-up cross-sectional view of another embodiment of theelectrodes of the device of FIG. 5 taken along line 10-10 of FIG. 5;

FIG. 13 is a perspective view of the device of FIG. 5 cutting tissue;

FIG. 14 is a close-up view of a distal end portion of the device of FIG.5 with an exemplary fluid coupling to a tissue surface of tissue;

FIG. 15 is a perspective view of another embodiment of anelectrosurgical device according to the present invention;

FIG. 16 is a close-up view of the shaft of the device of FIG. 15;

FIG. 17 is a close-up longitudinal cross-sectional view of the shaft ofthe device of FIG. 15;

FIG. 18 is a close-up view of the electrodes of the device of FIG. 15with an exemplary fluid coupling to a tissue surface of tissue;

FIG. 19 is a close-up cross-sectional view of the device of FIG. 15taken along line 19-19 with another view of a fluid coupling to a tissuesurface of tissue;

FIG. 20 is a close-up view of another embodiment of the fluid outlet(s)of the device of FIG. 15;

FIG. 21 is a is a close-up view of another embodiment of the electrodesof the device of FIG. 15;

FIG. 22 is a perspective view of a distal portion of another embodimentof an electrosurgical device according to the present invention;

FIG. 23 is a perspective view of a distal portion of another embodimentof the electrosurgical device of FIG. 22 according to the presentinvention;

FIG. 24 is a perspective view of a distal portion of another embodimentof an electrosurgical device according to the present invention; and

FIG. 25 is a perspective view of a distal portion of another embodimentof the electrosurgical device of FIG. 24 according to the presentinvention.

DETAILED DESCRIPTION

Throughout the description, like reference numerals and letters indicatecorresponding structure throughout the several views. Also, anyparticular feature(s) of a particular exemplary embodiment may beequally applied to any other exemplary embodiment(s) of thisspecification as suitable. In other words, features between the variousexemplary embodiments described herein are interchangeable as suitable,and not exclusive. From the specification, it should be clear that anyuse of the terms “distal” and “proximal” are made in reference to theuser of the device, and not the patient.

The invention provides systems, devices and methods to control tissuetemperature at a tissue treatment site during an electrosurgicalprocedure, as well as shrinking, coagulating, cutting and sealing tissueagainst blood and other fluid loss, for example, by shrinking the lumensof blood vessels (e.g., arteries, veins). The devices may be configured,due to the narrow electrode size, to fit through a trocar down to a sizeas small as 5 mm.

The invention will now be discussed with reference to the figures, withFIG. 1 showing a front view of one embodiment of a system of the presentinvention which may include an electrosurgical unit 10 in combinationwith a fluid source 20 and a handheld electrosurgical device 30. Inaddition, FIG. 1 shows a movable cart 2 having a support member 4comprising a hollow cylindrical post which carries a platform 6comprising a pedestal table to provide a flat, stable surface forlocation of the electrosurgical unit 10.

As shown, cart 2 further comprises a fluid source carrying pole 8 havinga height which may be adjusted by sliding the carrying pole 8 up anddown within the support member 4 and thereafter secured in position witha set screw. On the top of the fluid source carrying pole 8 is a crosssupport provided with loops at the ends thereof to provide a hook forcarrying fluid source 20.

As shown in FIG. 1, fluid source 20 may comprise a bag of fluid fromwhich fluid 12 may flow through a drip chamber 14, particularly afterthe bag is penetrated with a spike located at the end of the dripchamber 14. Thereafter, fluid 12 may flow through flexible andcompressible fluid delivery tubing 16 to handheld electrosurgical device30. The fluid delivery tubing 16 may be made from a synthetic polymermaterial, such as polyvinyl chloride.

As shown in FIG. 1, the fluid delivery tubing 16 passes through pump 22.As shown, pump 22 may comprise a peristaltic pump and, morespecifically, a rotary peristaltic pump. With a rotary peristaltic pump,a portion of the delivery tubing 16 may be loaded into the pump head byraising and lower the pump head in a known manner. Fluid 12 may then beconveyed within the delivery tubing 16 by waves of contraction placedexternally on the tubing 16 which may be produced mechanically,typically by rotating pinch rollers which rotate on a drive shaft andintermittently compress the tubing 16 against an anvil support.Peristaltic pumps may be particularly used, as the electro-mechanicalforce mechanism, here rollers driven by electric motor, does not makecontact the fluid 12, thus reducing the likelihood of inadvertentcontamination.

In the present embodiment the fluid 12 may particularly comprise liquidsaline solution, and even more particularly, normal (0.9% w/v NaCl orphysiologic) saline. Although the description herein may make referenceto saline as the fluid 12, other electrically conductive fluids may beused in accordance with the invention.

Additionally, while an electrically conductive fluid having anelectrically conductivity similar to normal saline may be preferred, aswill become more apparent with further reading of this specification,fluid 12 may also be an electrically non-conductive fluid. The use of anon-conductive fluid, while not providing all the advantage of anelectrically conductive fluid, still provides certain advantages overthe use of a dry electrode including, for example, reduced occurrence oftissue sticking to the electrode of device 30 and cooling of theelectrode and/or tissue. Therefore, it is also within the scope of theinvention to include the use of an electrically non-conductive fluid,such as, for example, deionized water.

Electrosurgical unit 10 may be particularly configured to provide bothmonopolar and bipolar radio-frequency (RF) power output. However,electrosurgical unit 10 may particularly include a lock out featurewhich prevents both monopolar and bipolar output from being activatedsimultaneously. Alternatively, rather than use a single electrosurgicalunit 10, device 30 may be simultaneously connected to two separateelectrosurgical units. For example, device 30 may be connected to afirst electrosurgical unit 10 to provide monopolar power output theretoand a second electrosurgical unit 10 to provide bipolar power outputthereto.

During monopolar operation of electrosurgical device 30, a firstelectrode, often referred to as the active electrode, may be providedwith electrosurgical device 30 while a second electrode, often referredto as the indifferent or neutral electrode, may be provided in the formof a ground pad dispersive electrode located on the patient (also knownas a patient return electrode), typically on the back or other suitableanatomical location. An electrical circuit may then be formed betweenthe active electrode and ground pad dispersive electrode with electricalcurrent flowing from the active electrode through the patient to groundpad dispersive electrode in a manner known in the art.

During bipolar operation of electrosurgical device 30, the ground padelectrode located on the patient is not required, and a second electrodeproviding a second electrical pole may be provided as part of thedevice. An alternating current electrical circuit may then be createdbetween the first and second electrical poles of the device.Consequently, alternating current no longer flows through the patient'sbody to the ground pad electrode, but rather through a localized portionof tissue between the poles of device 30. As indicated above, monopolarand bipolar power may be provided from electrosurgical unit 10 as knownin the art, or from separate electrosurgical units.

As shown in FIG. 1, electrosurgical device 30 may be connected toelectrosurgical unit 10 via electrical cables 24 and 26. Cable 24 isshown with a plug 34 which connects to bipolar output receptacle 38 ofelectrosurgical unit 10, while cable 26 is shown with a plug 42 whichconnects to the monopolar output receptacle 46 of electrosurgical unit10. Briefly turning to FIG. 6, when electrosurgical 10 may be used inmonopolar mode, additional cable 28 may connect a ground pad dispersiveelectrode 48 to the ground pad receptacle 56 of the electrosurgical unit10.

FIG. 2 shows the front panel of exemplary electrosurgical unit 10. Apower switch 58 may be used to turn the electrosurgical unit 10 on andoff. After turning the electrosurgical unit 10 on, an RF power settingdisplay 60 may be used to display the RF power setting numerically inwatts. The power setting display 60 may further comprise a liquidcrystal display (LCD).

Electrosurgical unit 10 may further include an RF power selector 62comprising RF power setting switches 62 a, 62 b which may be used toselect the RF power setting. Pushing the switch 62 a may increase the RFpower setting, while pushing the switch 62 b may decrease the RF powersetting. Electrosurgical unit 10 may also include an RF power activationdisplay 64 comprising an indicator light which may illuminate when RFpower is activated, either via a handswitch on device 30 or afootswitch. Switches 62 a, 62 b may comprise membrane switches. Itshould be understood that while only one RF power selector 62 is shown,electrosurgical unit 10 may have two such RF power selectors with oneeach for monopolar and bipolar power selection.

In addition to having a RF power setting display 60, electrosurgicalunit 10 may further include a fluid flow rate setting display 66. Flowrate setting display 66 may comprise three indicator lights 66 a, 66 band 66 c with first light 66 a corresponding to a fluid flow ratesetting of low, second light 66 b corresponding to a fluid flow ratesetting of medium (intermediate) and third light 66 c corresponding to aflow rate setting of high. One of these three indicator lights willilluminate when a fluid flow rate setting is selected.

Electrosurgical unit 10 may further include a fluid flow selector 68comprising flow rate setting switches 68 a, 68 b and 68 c used to selector switch the flow rate setting. Three push switches may be providedwith first switch 68 a corresponding to the fluid flow rate setting oflow, second switch 68 b corresponding to a fluid flow rate setting ofmedium (intermediate) and third switch 68 c corresponding to a flow ratesetting of high. Pushing one of these three switches may select thecorresponding flow rate setting of either low, medium (intermediate) orhigh. The medium, or intermediate, flow rate setting may beautomatically selected as the default setting if no setting is manuallyselected. Switches 68 a, 68 b and 68 c may comprise membrane switches.

Before starting a surgical procedure, it may be desirable to primedevice 30 with fluid 12. Priming may be desirable to inhibit RF poweractivation without the presence of fluid 12. A priming switch 70 may beused to initiate priming of device 30 with fluid 12. Pushing switch 70once may initiate operation of pump 22 for a predetermined time periodto prime device 30. After the time period is complete, the pump 22 mayshut off automatically. When priming of device 30 is initiated, apriming display 72 comprising an indicator light may illuminate duringthe priming cycle.

An exemplary bipolar RF power output curve of electrosurgical unit 10 isshown in FIG. 3. Impedance Z, shown in units of ohms on the X-axis andoutput power P_(O) is shown in units of watts on the Y-axis. In theillustrated embodiment, the bipolar electrosurgical power (RF) is set to200 watts. As shown in the figure, for an RF power setting P_(S) of 200watts, the output power P_(O) will remain constant with the set RF powerP_(S) as long as the impedance Z stays between the low impedance cut-offof 30 ohms and the high impedance cut-off of 120 ohms. Below animpedance Z of 30 ohms, the output power P_(O) will decrease as shown bythe low impedance ramp. Above an impedance Z of 120 ohms, the outputpower P_(O) will also decrease as shown by the high impedance ramp. Withrespect to monopolar power output, an exemplary monopolar RF poweroutput curve would include that of the Valleylab Force FX, either forcut or coagulation mode, hereby incorporated by reference.

Electrosurgical unit 10 may be configured such that the speed of pump22, and therefore the throughput of fluid 12 expelled by the pump 22, ispredetermined based on two input variables, the RF power setting and thefluid flow rate setting. In FIG. 4 there is shown an exemplaryfunctional relationship of fluid flow rate Q in units of cubiccentimetres per minute (cc/min) on the Y-axis, and the RF power settingP_(S) in units of watts on the X-axis. The relationship may beengineered to inhibit undesirable effects such as tissue desiccation,electrode sticking, smoke production and char formation, while at thesame time not providing a fluid flow rate Q at a corresponding RF powersetting P_(S) which is so great as to provide too much electricaldispersion and cooling at the electrode/tissue interface. While notbeing bound to a particular theory, a more detailed discussion on howthe fluid flow rate interacts with the radio frequency power, modes ofheat transfer away from the tissue, fractional boiling of the fluid andvarious control strategies may be found in U.S. Publication No.2001/0032002, published Oct. 18, 2001, assigned to the assignee of thepresent invention and hereby incorporated by reference in its entiretyto the extent it is consistent.

As shown in FIG. 4, electrosurgical unit 10 has been configured toincrease the fluid flow rate Q linearly with an increasing RF powersetting P_(S) for each of three fluid flow rate settings of low, mediumand high corresponding to Q_(L), Q_(M) and Q_(H), respectively.Conversely, electrosurgical unit 10 has been configured to decrease thefluid flow rate Q linearly with a decrease RF power setting P_(S) foreach of three fluid flow rate settings of low, medium and highcorresponding to Q_(L), Q_(M) and Q_(H), respectively.

An electrosurgical unit similar to exemplary electrosurgical unit 10 andhaving detailed schematic drawings, albeit without monopolar output, maybe found in U.S. Publication No. 2006/0149225, published Jul. 6, 2006,assigned to the assignee of the present invention and herebyincorporated by reference in its entirety to the extent it isconsistent.

While electrosurgical unit 10 as shown above includes an attached pump22, in other embodiments pump 22 may not be integrated withelectrosurgical unit 10, but rather be separate from electrosurgicalunit 10.

In still other embodiments, pump 22 may be eliminated and there may beno preset functional relationship of fluid flow rate Q versus RF powersetting P_(S) stored in the electrosurgical unit 10. In such aninstance, rather than the fluid flow rate Q being automaticallycontrolled by the electrosurgical unit 10 based on the RF power settingP_(S), the fluid flow rate Q may be manually controlled, such as by theuser of device 10 or another member of the surgical team, with a roller(pinch) clamp or other clamp provided with device 10 and configured toact upon and compress the tubing 16 and control flow in a manner knownin the art. Exemplary fluid flow control mechanisms may be found in U.S.Publication No. 2005/0090816, published Apr. 28, 2005, assigned to theassignee of the present invention and hereby incorporated by referencein its entirety to the extent it is consistent. An example of anelectrosurgical unit which does not include a pump, but may be used inconjunction with a manually operated fluid flow control mechanism ondevice 10, includes an electrosurgical unit such as the Valleylab ForceFX.

An exemplary bipolar and/or monopolar electrosurgical device of thepresent invention which may be used in conjunction with electrosurgicalunit 10 of the present invention is shown at reference character 30 a inFIG. 5. While various electrosurgical devices of the present inventionare described herein with reference to use with electrosurgical unit 10,it should be understood that the description of the combination is forpurposes of illustrating the system of the invention. Consequently, itshould be understood that while the electrosurgical devices disclosedherein may be disclosed for use with electrosurgical unit 10, it may beplausible to use other electrosurgical devices with electrosurgical unit10, or it may be plausible to use the electrosurgical devices disclosedherein with another electrosurgical unit.

As shown in FIG. 5, exemplary device 30 a includes an elongatedhandpiece 100 with a handle 101 comprising mating handle portions 101 a,101 b. Handpiece 100 may be configured to enable a user of device 30 ato hold and manipulate device 30 a between the thumb and index fingerlike a writing instrument. Handle 101 may comprise a sterilizable,rigid, electrically insulative material, such as a synthetic polymer(e.g., polycarbonate, acrylonitrile-butadiene- styrene).

Device 30 a further includes cables 24 and 26, as shown in FIG. 1, whichare connectable to electrosurgical unit 10 to provide device 30 a withbipolar and monopolar power output, respectively, from electrosurgicalunit 10. As further shown in FIG. 6, cable 24 of device 30 a maycomprise three insulated wire conductors 32 a, 32 b, 32 c connectable tobipolar power output receptacles 38 a, 38 b, 38 c of electrosurgicalunit 10 via three banana (male) plug connectors 36 a, 36 b, 36 c. Thebanana plug connectors 36 a, 36 b, 36 c may be each assembled withinsulated wire conductors 32 a, 32 b, 32 c within the housing of plug 34in a known manner. On device 30 a, insulated wire conductor 32 a may beconnected to a bipolar hand switch assembly 110, and insulated wireconductors 32 b and 32 c may be connected to a proximal portion ofelectrodes 102 a, 102 b, particularly by welding.

Electrodes 102 a, 102 b thereafter may extend through linear conduitsprovided by cylindrical through passages 104 a, 104 b of elongated,rigid, electrically insulative shaft 108 comprising shaft body 106.Shaft body 106 may comprise a sterilizable, rigid, electricallyinsulative material, such as a synthetic polymer (e.g., polycarbonate,acrylonitrile-butadiene-styrene). At the distal end of device 30, adistal portion of electrodes 102 a, 102 b having a U-shape loop extendsfrom the passages 104 a, 104 b of elongated shaft body 106.

Cable 26 of device 30 a may comprise two insulated wire conductors 40 a,40 b connectable to monopolar power output receptacles 46 a, 46 b ofelectrosurgical unit 10 via two banana (male) plug connectors 44 a, 44b. The banana plug connectors 44 a, 44 b may be each assembled withinsulated wire conductors 40 a, 40 b within the housing of plug 42 in aknown manner. On device 30 a, insulated wire conductor 40 a may beconnected to a monopolar hand switch assembly 112, and insulated wireconductor 40 b may be connected to a proximal portion of electrode 102 bof shaft 108. As shown wire conductors 32 b and 40 b may merge insidehandle 100 and share the same attachment location to electrode 102 b.

When device 30 a is used in monopolar mode, an additional cable 28 maybe utilized to connect a ground pad dispersive electrode 48, which isattached to the patient, to the electrosurgical unit 10 comprising wireconductor 50 and plug 52 at the end thereof having plug connector 54which connects to the ground pad receptacle 56.

Hand switch assemblies 110 and 112 may comprise push buttons 114 and116, respectively, which overlie domed switches on a platform comprisinga printed circuit board, with the construction and wiring of the handswitch assemblies 110 and 112 known in the art. Upon depression of pushbuttons 114 or 116, a domed switch beneath the push button forms aclosed circuit which is sensed by electrosurgical unit 10, which thenprovides bipolar or monopolar power, respectively. Exemplary handswitches may be found in U.S. Publication No. 2006/0149225, publishedJul. 6, 2006, and U.S. Publication No. 2005/0090816, published Apr. 28,2005, which are assigned to the assignee of the present invention andare hereby incorporated by reference in there entirety to the extentthey are consistent.

As shown FIG. 7, during use of device 30 a, fluid 12 from fluid source20 may be communicated through a tubular fluid passage provided byvarious structures. In the present embodiment, fluid 12 from the fluidsource 20 is first communicated through lumen 18 of delivery tubing 16.Fluid 12 may then flow through lumen 120 of a special pump tubingsegment 118 configured to operate specifically with the peristaltic pump22, which may be spliced in between portions of delivery tubing 16 andconnected thereto using barbed fluid line connectors 122 at each endthereof.

Within handle 101 of device 30 a, fluid delivery tubing 16 may beconnected to the inlet branch of a Y-splitter 124, which thereafterprovides two outlet branches which may be connected to the proximal endportion of delivery tubing segments 128 a, 128 b. A distal end portionof the delivery tubing segments 128 a, 128 b may be connected to shaftbody 106 by being inserted into cylindrical receptacles 132 a, 132 b(counter bores) of shaft body 106. Fluid 12 then may flow through lumens130 a, 130 b of delivery tubing segments 128 a, 128 b and into tubularpassages 134 a, 134 b formed in shaft body 106. Fluid 12 may then beexpelled from fluid delivery outlets 136 a, 136 b at the distal end 138of shaft body 106.

Alternatively, as shown in FIG. 8, fluid delivery tubing 16 may beinserted directly into receptacle 132 of shaft body 106. Fluid 12 thenmay flow through passage 134 before branching into passages 134 a, 134 bwithin shaft body 106 and being expelled from fluid delivery outlets 136a, 136 b. Also, alternatively, a single fluid outlet 136 may be locatedbetween the electrodes 102 a, 102 b, as shown in FIG. 10, in which caseoutlets 136 a, 136 b may be omitted.

FIG. 9 provides a close-up view of shaft body 106, U-shaped electrodes102 a, 102 b and fluid delivery outlets 136 a, 136 b. As shown, U-shapedelectrodes 102 a, 102 b may be arranged to provide two fixed, laterallyand spatially separated (by empty space) electrode tips which may beconfigured as mirror images in size and shape, and may have a blunt,rounded distal end which provides a smooth continuous surface (which isdevoid of points or edges) to treat tissue. As shown, U-shapedelectrodes 102 a, 102 b may be coplanar (i.e. in the same plane).

U-shaped electrodes 102 a, 102 b, which are adjacent the distal end 138of shaft body 106, may each comprise lateral longitudinal segments 140a, 140 b and medial longitudinal segments 142 a, 142 b which extenddistally from the distal end 138 of shaft body 106 and are proximal toan arcuate distal segments 144 a, 144 b. It should be understood thatwhile the electrodes 102 a, 102 b have been described as having varioussegments, the description is aimed to provide orientation of suchrelative to the device, and not that the electrodes 102 a, 102 b arenecessarily provided from separately formed individual segments whichhave been joined together. To the contrary, each electrode 102 a, 102 bmay be particularly formed from a single continuous member, such as asingle continuous piece of wire described in greater detail below.

As shown, the arcuate distal segments are continuously arcuate from onelongitudinal segment to the other longitudinal segment without anyinterruptions, and more particularly may be semicircular with a radiusof 180 degrees. Also as shown, fluid delivery outlet 136 a is locatedbetween longitudinal segments 140 a, 142 a, and fluid delivery outlet136 b is located between longitudinal segments 140 b, 142 b. In thismanner, fluid 12 expelled from fluid delivery outlets 136 a, 136 b maybetter form a fluid membrane between longitudinal segments 140 a, 142 aand 140 b, 142 b, respectively, as discussed in greater detail below.

Returning to FIG. 7, the lateral longitudinal segments 140 a, 140 bextend through the length of shaft body 106. However, the mediallongitudinal segments 142 a, 142 b are retained in (e.g.interference/friction fit) and extend from a receptacles (blind bores)146 a, 146 b formed in the distal end of shaft body 106. As shown in thefigures, lateral longitudinal segments 140 a, 140 b and mediallongitudinal segments 142 a, 142 b are all parallel and coplanar (in thesame plane).

Electrodes 102 a, 102 b may particularly be formed from single strand,metal (particularly stainless steel) wire. Each electrode 102 a, 102 bmay have an overall (exposed) length L in the range of and any incrementbetween 4 mm to 15 mm, and more particularly 6 mm to 12 mm. Eachelectrode 102 a, 102 b may have a width W in the range of and anyincrement between 1 mm to 4 mm, and more particularly 2 mm to 3 mm.

As shown in FIG. 10, the wire may be cylindrical and have a circularcross-sectional profile with a cross-section thickness, here diameter,in a range of and any increment between 0.1 mm to 1.5 mm, and moreparticularly 0.5 mm to 1 mm, and even more particularly 0.6 to 0.75 mm.

With respect to spacing, the spatial gap separation GS betweenelectrodes 102 a, 102 b may be in the range of and any increment between0.1 mm to 3 mm, and more particularly 0.5 mm to 2 mm, and even moreparticularly 0.75 mm to 1.5 mm. The spacing between the medial 142 a,142 b and lateral segments 140 a, 140 b of each electrode 102 a, 102 bmay be in a range of and any increment between 0.1 mm to 3 mm, and moreparticularly 0.5 mm to 2 mm, and even more particularly 0.75 mm to 1.5mm.

As shown in FIG. 11, at least a portion of the length of laterallongitudinal segment 140 b may be shaped, particularly from circularwire by grinding or sanding, as to have a cross-sectional profile withopposing sides 150 b/152 b which converge laterally to provide a wedgeshaped blade portion 154 b on the perimeter which terminates in a linearlateral cutting edge 156 b which extends longitudinally along the lengthof longitudinal segment 140 b. As shown, in alternative embodiments, anyof the remaining longitudinal segments 140 a, 142 a or 142 b may havethe same cross-sectional profile as segment 140 b.

As shown in FIG. 11, blade portion 154 b narrows as the opposing sides150 b/152 b approach cutting edge 156 b. More particularly, the sides150 b/152 b of blade portion 154 b are planar. However, in otherembodiments, sides 150 b/152 b may be concave or convex.

As shown in FIG. 12, at least a portion of the length of laterallongitudinal segment 140 b may be shaped, particularly from circularwire by grinding or sanding, as to have a profile with opposing sides150 b/152 b which are substantially parallel and terminate in linearlateral cutting edge 156 b which extends longitudinally along the lengthof longitudinal segment 140 b. As shown, in alternative embodiments, anyof the remaining longitudinal segments 140 a, 142 a or 142 b may havethe same profile as segment 140 b. Here, segment 140 has a polygonalprofile, and more particularly a rectangular profile.

For the electrodes 102 a, 102 b shown in FIGS. 11 and 12, lateralcutting edge 156 b may be particularly configured to cut tissueelectrosurgically in the presence of monopolar radio frequency energyfrom electrosurgical unit 10 as to provide an electrosurgical cuttingedge, but without any fluid 12 being provided from fluid source 20.However, in other embodiments, lateral cutting edge 156 b may beconfigured to cut tissue with fluid 12 being provided simultaneouslyfrom device 30 a, or be configured to cut tissue mechanically(sharpened) without electrosurgical energy. Referring now to FIG. 13,device 30 a may be used to cut tissue by applying cutting edge 156 b ofelectrode 102 b to tissue 200, and repeatedly moving the electrode 102 balong a desired incision or resection line in the tissue to form thedepicted crevice.

While cutting edge 156 b may be particularly configured to cut tissuewith monopolar RF energy and without fluid 12 being expelled from device30 a, arcuate distal end segments 144 a, 144 b may be particularlyconfigured to slide or otherwise move across a tissue surface in thepresence of bipolar radio frequency energy from electrosurgical unit 10and fluid 12 from the fluid source 20.

As shown in FIG. 14, one way in which device 30 a may be used as abipolar device is with the longitudinal axis of electrodes 102 a, 102 bvertically orientated, and the arcuate distal segments 144 a, 144 b ofelectrodes 102 a, 102 b laterally spaced adjacent tissue surface 202 oftissue 200. When device 30 a is used in this manner, electrodes 102 a,102 b may be connected to electrosurgical unit 10 and receive bipolarradio frequency energy which forms an alternating current electricalfield in tissue 200 located between electrodes 102 a, 102 b. In thepresence of alternating current, the electrodes 102 a, 102 b alternatepolarity between positive and negative charges with current flow fromthe positive to negative charge. Without being bound to a particulartheory, heating of the tissue is performed by electrical resistanceheating.

Fluid 12, in addition to providing an electrical coupling between thedevice 30 a and tissue 200, lubricates surface 202 of tissue 200 andfacilitates the movement of electrodes 102 a, 102 b across surface 202of tissue 200. During movement of electrodes 102 a, 102 b, electrodes102 a, 102 b typically slide across the surface 202 of tissue 200.Typically the user of device 30 a slides electrodes 102 a, 102 b acrosssurface 202 of tissue 200 back and forth with a painting motion whileusing fluid 12 as, among other things, a lubricating coating. Preferablythe thickness of the fluid 12 between the arcuate distal segments 144 a,144 b of electrodes 102 a, 102 b and surface 202 of tissue 200 at theouter edge of couplings 204 a, 204 b is in the range of 0.05 mm to 1.5mm. Also, in certain embodiments, the arcuate distal segments 144 a, 144b of electrodes 102 a, 102 b may contact surface 202 of tissue 200without any fluid 12 in between.

As shown in FIG. 14, fluid 12 expelled from fluid outlets 136 a, 136 bmay flow distally on electrodes 102 a, 102 b in the form of droplets 208a, 208 b or as a membrane 210 a, 210 b extending across the U-shapedapertures 160 a, 160 b and bridging between longitudinal segments 140a,142 a and 140 b,142 b of electrodes 102 a, 102 b. As shown in FIG. 14,droplets 208 a, 208 b may form at varying times from fluid 12 expelledfrom fluid outlets 136 a, 136 b. Also, fluid 12 may be expelled invarying quantity from each of the fluid outlets 136 a, 136 b, dependingon, for example, device orientation, pressure, flow rate and varyingfluid outlet sizes. With use of device 30 a, the physicalcharacteristics of the droplets 208 a, 208 b and the membranes 210 a,210 b may also vary due to changes in the surface finish of theelectrodes 102 a, 102 b. For example, the membranes 210 a, 210 b mayform a meniscus type curvature at either end thereof as they progressdistally along electrodes 102 a, 102 b.

Fluid 12 in the form of membranes 210 a, 210 b bridging apertures 160 a,160 b may offer certain advantages over droplets 208, 208 b as themembranes 210 a, 210 b, after flowing distally along the longitudinalsegments of electrodes 102 a, 102 b, may be more evenly distributed overarcuate distal segments 144 a, 144 b of electrodes 102 a, 102 b, to thenform fluid couplings 204 a, 204 b. Also, membranes 210 a, 210 b mayexhibit better retention to electrodes 102 a, 102 b while flowingdistally along electrodes 102 a, 102 b and not fall off as may be thesituation for droplets 208 a, 208 b.

As shown in FIG. 14, fluid couplings 204 a, 204 b may particularlycomprise discrete, localized webs and more specifically comprisetriangular shaped webs of fluid 12 between surface 202 of tissue 200 andelectrodes 102 a, 102 b. When the user of electrosurgical device 30 aplaces electrodes 102 a, 102 b at a tissue treatment site and moveselectrodes 102 a, 102 b across the surface 202 of the tissue 200, fluid12 is expelled from fluid outlets 136 a, 136 b around the surfaces ofelectrodes 102 a, 102 b and onto the surface 202 of the tissue 200 viacouplings 204 a, 204 b. At the same time, RF electrical energy, shown byelectrical field lines 206, is provided to tissue 200 at tissue surface202 and below tissue surface 202 into tissue 200 through fluid couplings204 a, 204 b. In the foregoing manner, device 30 a may be used to sealtissue against blood and other fluid loss.

Thus, while cutting edge 156 b may be particularly configured to cuttissue with monopolar RF energy and without fluid 12 being expelled fromdevice 30 a, arcuate distal end segments 144 a, 144 b may beparticularly configured to slide or otherwise move across a tissuesurface in the presence of bipolar radio frequency energy fromelectrosurgical unit 10 and fluid 12 from the fluid source 20.

Another embodiment of device 30 is shown in FIGS. 15-18 as device 30 b.As shown, rather the U-shaped electrodes being spaced side-by-side aswith embodiment 30 a, the U-shaped electrodes are arranged such that theperimeter of U-shaped electrode 102 a is surrounded by U-shapedelectrode 102 b, with U-shaped electrode 102 a located within theU-shaped aperture 160 b defined by electrode 102 b. In this manner, thetwo longitudinal segments 140 a, 142 a of electrode 102 a are now medialto the two longitudinal segments 140 b, 142 b of electrode 102 b.Vice-versa, the two longitudinal segments 140 b, 142 b of electrode 102b are now lateral to the two longitudinal segments 140 a, 142 a ofelectrode 102 a. As compared with device 30 a, the electrodeconfiguration of device 30 b may be somewhat narrower, which may makedevice 30 b less intrusive than device 30 a and afford device 30 bgreater access to more confined locations with greater visibility.

As shown arcuate distal segments 144 a, 144 b of electrodes 102 a, 102 bmay be concentric. In other words, arcuate distal segments 144 a, 144 bmay have a common center point CP. As shown, similar to embodiment 30 a,U-shaped electrodes 102 a, 102 b are coplanar (in the same plane). Alsosimilar to embodiment 30 a, longitudinal segments 140 a, 140 b andlongitudinal segments 142 a, 142 b are all parallel and coplanar (in thesame plane). Also similar to embodiment 30 a, U-shaped electrodes 102 a,102 b may have the same cross-sectional profiles as set forth in FIGS.10-12. In this manner, electrode 102 b may still include cutting edge156 b particularly configured to cut tissue with monopolar RF energy andwithout fluid 12 being expelled from device 30 b.

As shown in FIGS. 18-19, one way in which device 30 b may be used as abipolar device is with the longitudinal axis of electrodes 102 a, 102 bsubstantially horizontally orientated. When device 30 a is used in thismanner, electrodes 102 a, 102 b may be connected to electrosurgical unit10 and receive bipolar radio frequency energy which forms an alternatingcurrent electrical field in tissue 200 located between electrodes 102 a,102 b and fluid 12 provided from device 30 b.

Fluid 12, in addition to providing an electrical coupling between thedevice 30 a and tissue 200, lubricates surface 202 of tissue 200 andfacilitates the movement of electrodes 102 a, 102 b across surface 202of tissue 200. As shown in FIGS. 18-19, fluid 12 expelled from fluidoutlet 136 may form fluid couplings 204.

As shown in FIG. 19, fluid couplings 204 may particularly compriselocalized webs and more specifically comprise triangular shaped webs offluid 12 between surface 202 of tissue 200 and electrodes 102 a, 102 b.When the user of electrosurgical device 30 b places electrodes 102 a,102 b at a tissue treatment site and moves electrodes 102 a, 102 bacross the surface 202 of the tissue 200, fluid 12 is expelled fromfluid outlet 136 around the surfaces of electrodes 102 a, 102 b and ontothe surface 202 of the tissue 200 via couplings 204. At the same time,RF electrical energy, shown by electrical field lines 206, is providedto tissue 200 at tissue surface 202 and below tissue surface 202 intotissue 200 through fluid couplings 204. In the foregoing manner, device30 b may be used to seal tissue against blood and other fluid loss.

As shown in FIGS. 15-19, fluid outlet 136 may be located betweenlongitudinal segments 140 a, 142 a of electrodes 102 a. As shown in FIG.20, a fluid outlet 136 may be located between longitudinal segments 142a of electrode 102 a and longitudinal segment 142 b of electrode 102 b.A fluid outlet 136 may also be located between longitudinal segments 140a of electrode 102 a and longitudinal segment 140 b of electrode 102 b.In various embodiments, any fluid outlet 136 may be used individually orin combination with any other of fluid outlet(s) 136 as shown. Forexample, one or both of the fluid outlets 136 shown in FIG. 20 may beused in combination with the fluid outlet 136 shown in FIGS. 15-19.

For the embodiment of device 30 b shown in FIGS. 15-19, outer electrode102 b has the same cross-sectional profile with a thickness, herediameter, equal to the diameter of inner electrode 102 a. However, asshown in FIG. 21, outer electrode 102 b may have a smallercross-sectional profile with a thickness, here diameter, than innerelectrode 102 a, to better facilitate cutting with a narrower incision,as well as better conforming to the tissue surface during sealingtissue, particularly by deforming when a slight pressure is applied bythe user.

In another embodiment of the device 30, shown as device 30 c in FIG. 22,electrode 102 a may comprise a single longitudinal segment 166 ratherthan having a U-shape. Similar to device 30 b, the perimeter ofelectrode 102 a is surrounded by U-shaped electrode 102 b, withelectrode 102 a located within the U-shaped aperture 160 b defined byelectrode 102 b. In this manner, the longitudinal segment 166 ofelectrode 102 a is medial to the two longitudinal segments 140 b, 142 bof electrode 102 b. Vice-versa, the two longitudinal segments 140 b, 142b of electrode 102 b are lateral to longitudinal segment 166 ofelectrode 102 a. As compared with device 30 b, the electrodeconfiguration of device 30 c may be somewhat narrower, which may makedevice 30 c less intrusive than device 30 b and afford device 30 cgreater access to more confined locations with greater visibility.

As shown, similar to embodiments 30 a and 30 b, electrodes 102 a, 102 bare coplanar (in the same plane). Also similar to embodiments 30 a and30 b, longitudinal segment 166 and longitudinal segments 142 a, 142 bare all parallel and coplanar (in the same plane). Also similar toembodiments 30 a and 30 b, electrodes 102 a, 102 b may have the samecross-sectional profiles as set forth in FIGS. 10-12. In this manner,electrode 102 b may still include cutting edge 156 b particularlyconfigured to cut tissue with monopolar RF energy and without fluid 12being expelled from device 30 c.

As shown in FIG. 22, a fluid outlet 136 may be located betweenlongitudinal segment 166 of electrode 102 a and longitudinal segment 142b of electrode 102 b. A fluid outlet 136 may also be located betweenlongitudinal segment 166 of electrode 102 a and longitudinal segment 140b of electrode 102 b. Device 30 c may be used similar to device 30 b tocut and seal tissue as described herein. In an alternative embodiment,as shown in FIG. 23, an electrical insulator 164, such as formed from asynthetic polymer (e.g. acetal), may be located between the twoelectrodes 102 a, 102 b, and particularly between the distal end ofelectrode 102 a and the arcuate segment 144 b of electrode 102 b tobetter hold the position of the electrodes 102 a, 102 b relative to oneanother.

In another embodiment of the device 30, shown as device 30 d in FIG. 24,electrode 102 a may take the form of a longitudinally orientatedelongated blade shaped member 170 with a planar body, such as may beprovided by a flattened portion of metal (e.g. stainless steel) tubing172 which has been inserted in tubular passage 134 of shaft body 106. Inthis manner, lumen 18 of fluid delivery tubing 16 may be in fluidcommunication with lumen 174 of metal tubing 172 such that fluid 12 maybe expelled from fluid delivery outlet 136 adjacent the opposing sides178, 180 of the blade member 170 as defined by the tubing 172, andinsulated wire conductor 32 c may be connected to a proximal portion ofthe tubing, particularly by welding. With regards to dimensions, blademember 170 of electrode 102 a may have a length in the range of and anyincrement between 4 mm to 15 mm, and more particularly 6 mm to 12 mm.Blade 145 may have a width in the range of and any increment between 1mm to 4 mm, and more particularly 2 mm to 3 mm.

Similar to devices 30 b and 30 c, the perimeter of electrode 102 a issurrounded by U-shaped electrode 102 b, with electrode 102 a locatedwithin the U-shaped aperture 160 b defined by electrode 102 b. In thismanner, the blade member 170 of electrode 102 a is medial to the twolongitudinal segments 140 b, 142 b of electrode 102 b. Vice-versa, thetwo longitudinal segments 140 b, 142 b of electrode 102 b are lateral toblade member 170 of electrode 102 a.

As shown, similar to embodiments 30 a-30 c, electrodes 102 a, 102 b arecoplanar (in the same plane). Also similar to embodiments 30 a-30 c,blade member 170 and longitudinal segments 142 a, 142 b are all paralleland coplanar (in the same plane). Also similar to embodiments 30 a-30 c,electrode 102 b may have the same cross-sectional profiles as set forthin FIGS. 10-12. In this manner, electrode 102 b may still includecutting edge 156 b particularly configured to cut tissue with monopolarRF energy and without fluid 12 being expelled from device 30 c.

The perimeter 176 of blade member 170 from one (top) side 178 to theother (bottom) side 180 may be semi-circular as shown, or may have annarrow or pointed edge 156 b as shown in either of FIG. 11 or 12. Also,as shown the distal end 182 of blade member 170 is arcuate, and moreparticular semi-circular, across the width of the blade member 170. Alsoas shown, the arcuate distal segment 144 b of electrode 102 b and thearcuate distal end 182 of blade member 170 may be concentric. As shownin FIG. 25, the fluid outlet 136 may be orientated parallel with thelongitudinal perimeter of the blade member 170 to better feed fluid 16directly into aperture 160 b.

As compared to devices 30 b and 30 c, device 30 d and particularlyelectrode 102 b may be expected to cut tissue in a similar manner. Withregards to sealing tissue, device 30 d may be able to seal larger areasof tissue from blood and other fluid loss by having an increased surfacearea of electrode 102 as provided by blade member 170.

Device 30 and the various embodiments disclosed herein, such as 30 a-30d, may be particularly useful to surgeons to achieve hemostasis aftercutting through soft tissue, as part of hip or knee arthroplasty. Theelectrodes 102 a, 102 b of device 30 may be moved with a painting motionover the raw, oozing surface 202 of tissue 200 to seal the tissue 200against bleeding, or focused on individual larger bleeding vessels tostop vessel bleeding. As part of the same or different procedure, device30 may be useful to stop bleeding from the surface of cut bone, orosseous, tissue as part of any orthopaedic procedure that requires boneto be cut. Device 30 may be particularly useful for use duringorthopedic knee, hip, shoulder and spine procedures. Additionaldiscussion concerning such procedures may be found in U.S. PublicationNo. 2006/0149225, published Jul. 6, 2006, and U.S. Publication No.2005/0090816, published Apr. 28, 2005, which are assigned to theassignee of the present invention and are hereby incorporated byreference in there entirety to the extent they are consistent.

Device 30, and the various embodiments disclosed herein, such as 30 a-30d, may be particularly useful as non-coaptive devices that providecutting of tissue, as well as coagulation, hemostasis and sealing oftissue to inhibit blood and other fluid loss during surgery. In otherwords, grasping of the tissue is not necessary to shrink, coagulate, cutand seal tissue against blood loss, for example, by shrinking collagenand associated lumens of blood vessels (e.g., arteries, veins) toprovided the desired hemostasis of the tissue. Furthermore, due to theconfiguration of the electrodes, the electrodes may be easily bent by auser of the devices as needed. The electrodes may also be used for otherfunctions, such as providing a spoon like platform for scooping oftissue, such as an abnormal tissue mass (e.g. cancer). Furthermore, thecontrol system of the electrosurgical unit 10 is not necessarilydependent on tissue feedback such as temperature or impedance tooperate. Thus, the control system of electrosurgical unit 10 may be openloop with respect to the tissue which simplifies use.

As established above, device 30 of the present invention inhibit suchundesirable effects of tissue desiccation, electrode sticking, charformation and smoke generation, and thus do not suffer from the samedrawbacks as prior art dry tip electrosurgical devices. The use of thedisclosed devices can result in significantly lower blood loss duringsurgical procedures. Such a reduction in blood loss can reduce oreliminate the need for blood transfusions, and thus the cost andnegative clinical consequences associated with blood transfusions, suchas prolonged hospitalization.

While a preferred embodiment of the present invention has beendescribed, it should be understood that various changes, adaptations andmodifications can be made therein without departing from the spirit ofthe invention and the scope of the appended claims. The scope of theinvention should, therefore, be determined not with reference to theabove description, but instead should be determined with reference tothe appended claims along with their full scope of equivalents.Furthermore, it should be understood that the appended claims do notnecessarily comprise the broadest scope of the invention which theApplicant is entitled to claim, or the only manner(s) in which theinvention may be claimed, or that all recited features are necessary.

All publications and patent documents cited in this application areincorporated by reference in their entirety for all purposes to theextent they are consistent.

1. An electrosurgical device comprising: a handle; a shaft distal to thehandle; a first electrode tip and a second electrode tip adjacent adistal end of the shaft, the first electrode tip coplanar with thesecond electrode tip and wherein the first electrode tip comprises afirst wire electrode having a U-shape and the second electrode tipcomprises a second wire electrode having a U-shape; and at least onefluid outlet.
 2. The device of claim 1 wherein: each of the first andsecond U-shape electrodes comprises an arcuate distal segment and twolongitudinal segments extending distally relative to a distal end of theshaft.
 3. The device of claim 2 wherein: the arcuate distal segment ofeach of the first and second U-shape electrodes is arcuate from onelongitudinal segment to the other longitudinal segment.
 4. The device ofclaim 2 wherein: the arcute distal segment of each of the first andsecond U-shape electrodes is semicircular between the two longitudinalsegments.
 5. The device of claim 1 wherein: at least one of the U-shapeelectrodes provides a cutting edge.
 6. The device of claim 5 wherein:the cutting edge is an electrosurgical cutting edge.
 7. The device ofclaim 5 wherein: the cutting edge is arranged along a longitudinallength of the U-shape electrode.
 8. The device of claim 5 wherein: thecutting edge is straight.
 9. The device of claim 1 wherein: the firstelectrode and a second electrode are formed from metal wire.
 10. Thedevice of claim 9 wherein: the metal wire is single strand wire.
 11. Thedevice of claim 9 wherein: the metal wire is circular wire.
 12. Thedevice of claim 9 wherein: the metal wire is stainless steel wire. 13.The device of claim 1 wherein: the at least one fluid outlet is locateda distal end of the shaft.
 14. The device of claim 1 wherein: each ofthe first and second U-shape electrodes comprises two longitudinalsegments extending distally relative to a distal end of the shaft; andthe at least one fluid outlet is located between the two longitudinalsegments of at least one of the U-shape electrodes.
 15. The device ofclaim 1 wherein: each of the first and second U-shape electrodescomprises two longitudinal segments extending distally relative to adistal end of the shaft; the at least one fluid outlet comprises a firstfluid outlet and second fluid outlet; the first fluid outlet is locatedbetween the two longitudinal segments of the first U-shape electrode;and the second fluid outlet is located between the two longitudinalsegments of the second U-shape electrode.
 16. The device of claim 1wherein: the U-shape electrodes are coplanar.
 17. The device of claim 1wherein: each of the first and second U-shape electrodes comprises twolongitudinal segments extending distally relative to a distal end of theshaft; and the two longitudinal segments of the first U-shape electrodeand the two longitudinal segments of the second U-shape electrode areparallel.
 18. The device of claim 1 wherein: each of the first andsecond U-shape electrodes comprises two longitudinal segments extendingdistally relative to a distal end of the shaft; and the two longitudinalsegments of the first U-shape electrode and the two longitudinalsegments of the second U-shape electrode are all in a single plane. 19.The device of claim 1 wherein: each of the first and second U-shapeelectrodes comprises two longitudinal segments extending distallyrelative to a distal end of the shaft; and one longitudinal segments ofeach of the first and second U-shape electrodes is a medial longitudinalsegment and the other longitudinal segment is a lateral longitudinalsegment.
 20. The device of claim 1 wherein: each of the first and secondU-shape electrodes comprises two longitudinal segments extendingdistally relative to a distal end of the shaft; and the two longitudinalsegments of the second U-shape electrode are medial relative to the twolongitudinal segments of the first U-shape electrode.
 21. The device ofclaim 1 wherein: the first U-shape electrode surrounds a perimeter ofthe second U-shape electrode.
 22. The device of claim 1 wherein: thesecond U-shape electrode is located within a U-shape aperture defined bythe first U-shape electrode.
 23. The device of claim 1 wherein: each ofthe first and second U-shape electrodes comprises an arcute distalsegment; and the arcuate distal end segments are concentric.
 24. Thedevice of claim 1 wherein: the first U-shape electrode and the secondU-shape electrode have at least one of a same size and a same shape. 25.The device of claim 1 wherein: a position of first U-shape electrode anda position of the second U-shape electrode are fixed relative to oneanother.
 26. The device of claim 1 wherein: the device is configured tooperate as bipolar device and a monopolar device.
 27. An electrosurgicaldevice comprising: a handle; a shaft distal to the handle; a firstelectrode and a second electrode adjacent a distal end of the shaft, thefirst electrode coplanar with the second electrode and comprising a wireelectrode having a U-shape which surrounds a perimeter of the secondelectrode and is spaced from the second electrode by an aperture. 28.The device of claim 27 wherein: the second electrode comprises a wireelectrode having a linear segment.
 29. The device of claim 27 wherein:the second electrode comprises a wire electrode having a U-shape. 30.The device of claim 27 wherein: the second electrode comprises a bladeshaped member.
 31. The device of claim 27 further comprising: at leastone fluid outlet.